The intent of child resistant closure (CRC) technology is to eliminate the danger of misuse of potentially dangerous products or substances by children. However, many of the current closure designs either fail during their useful life or are too difficult for the elderly and others with debilitating diseases to use. In response to the inadequacies of the closure design, consumers frequently disable or remove the CRC, creating a serious safety hazard. This study will demonstrate the feasibility of a computer based design and analysis tool that will lead to improved safety, ease of use and consumer acceptance of CRC designs. The Phase I study will integrate materials engineering, computer graphics and engineering simulation technology. Computer based modeling methodology that includes the complex behavior of plastic materials when subjected to assembly and usage forces will be created. Once pilot tested, this design tool will be used to predict and optimize the short and long term performance and function of CRC's. Successful completion of both Phase I and Phase II will enable industrial design firms, custom injection molders and consumer products companies to produce safer, more effective closure designs.